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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Defines interfaces for interacting wtih the Raspberry Pi firmware's
4 * property channel.
5 *
6 * Copyright © 2015 Broadcom
7 */
8
9#include <linux/dma-mapping.h>
10#include <linux/mailbox_client.h>
11#include <linux/module.h>
12#include <linux/of_platform.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15#include <linux/pci.h>
16#include <linux/delay.h>
17#include <soc/bcm2835/raspberrypi-firmware.h>
18
19#define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
20#define MBOX_CHAN(msg) ((msg) & 0xf)
21#define MBOX_DATA28(msg) ((msg) & ~0xf)
22#define MBOX_CHAN_PROPERTY 8
23
24#define VL805_PCI_CONFIG_VERSION_OFFSET 0x50
25
26static struct platform_device *rpi_hwmon;
27static struct platform_device *rpi_clk;
28
29struct rpi_firmware {
30 struct mbox_client cl;
31 struct mbox_chan *chan; /* The property channel. */
32 struct completion c;
33 u32 enabled;
34};
35
36static DEFINE_MUTEX(transaction_lock);
37
38static void response_callback(struct mbox_client *cl, void *msg)
39{
40 struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
41 complete(&fw->c);
42}
43
44/*
45 * Sends a request to the firmware through the BCM2835 mailbox driver,
46 * and synchronously waits for the reply.
47 */
48static int
49rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
50{
51 u32 message = MBOX_MSG(chan, data);
52 int ret;
53
54 WARN_ON(data & 0xf);
55
56 mutex_lock(&transaction_lock);
57 reinit_completion(&fw->c);
58 ret = mbox_send_message(fw->chan, &message);
59 if (ret >= 0) {
60 if (wait_for_completion_timeout(&fw->c, HZ)) {
61 ret = 0;
62 } else {
63 ret = -ETIMEDOUT;
64 WARN_ONCE(1, "Firmware transaction timeout");
65 }
66 } else {
67 dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
68 }
69 mutex_unlock(&transaction_lock);
70
71 return ret;
72}
73
74/**
75 * rpi_firmware_property_list - Submit firmware property list
76 * @fw: Pointer to firmware structure from rpi_firmware_get().
77 * @data: Buffer holding tags.
78 * @tag_size: Size of tags buffer.
79 *
80 * Submits a set of concatenated tags to the VPU firmware through the
81 * mailbox property interface.
82 *
83 * The buffer header and the ending tag are added by this function and
84 * don't need to be supplied, just the actual tags for your operation.
85 * See struct rpi_firmware_property_tag_header for the per-tag
86 * structure.
87 */
88int rpi_firmware_property_list(struct rpi_firmware *fw,
89 void *data, size_t tag_size)
90{
91 size_t size = tag_size + 12;
92 u32 *buf;
93 dma_addr_t bus_addr;
94 int ret;
95
96 /* Packets are processed a dword at a time. */
97 if (size & 3)
98 return -EINVAL;
99
100 buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr,
101 GFP_ATOMIC);
102 if (!buf)
103 return -ENOMEM;
104
105 /* The firmware will error out without parsing in this case. */
106 WARN_ON(size >= 1024 * 1024);
107
108 buf[0] = size;
109 buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
110 memcpy(&buf[2], data, tag_size);
111 buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
112 wmb();
113
114 ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
115
116 rmb();
117 memcpy(data, &buf[2], tag_size);
118 if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
119 /*
120 * The tag name here might not be the one causing the
121 * error, if there were multiple tags in the request.
122 * But single-tag is the most common, so go with it.
123 */
124 dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
125 buf[2], buf[1]);
126 ret = -EINVAL;
127 }
128
129 dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr);
130
131 return ret;
132}
133EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
134
135/**
136 * rpi_firmware_property - Submit single firmware property
137 * @fw: Pointer to firmware structure from rpi_firmware_get().
138 * @tag: One of enum_mbox_property_tag.
139 * @tag_data: Tag data buffer.
140 * @buf_size: Buffer size.
141 *
142 * Submits a single tag to the VPU firmware through the mailbox
143 * property interface.
144 *
145 * This is a convenience wrapper around
146 * rpi_firmware_property_list() to avoid some of the
147 * boilerplate in property calls.
148 */
149int rpi_firmware_property(struct rpi_firmware *fw,
150 u32 tag, void *tag_data, size_t buf_size)
151{
152 struct rpi_firmware_property_tag_header *header;
153 int ret;
154
155 /* Some mailboxes can use over 1k bytes. Rather than checking
156 * size and using stack or kmalloc depending on requirements,
157 * just use kmalloc. Mailboxes don't get called enough to worry
158 * too much about the time taken in the allocation.
159 */
160 void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL);
161
162 if (!data)
163 return -ENOMEM;
164
165 header = data;
166 header->tag = tag;
167 header->buf_size = buf_size;
168 header->req_resp_size = 0;
169 memcpy(data + sizeof(*header), tag_data, buf_size);
170
171 ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header));
172
173 memcpy(tag_data, data + sizeof(*header), buf_size);
174
175 kfree(data);
176
177 return ret;
178}
179EXPORT_SYMBOL_GPL(rpi_firmware_property);
180
181static void
182rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
183{
184 time64_t date_and_time;
185 u32 packet;
186 int ret = rpi_firmware_property(fw,
187 RPI_FIRMWARE_GET_FIRMWARE_REVISION,
188 &packet, sizeof(packet));
189
190 if (ret)
191 return;
192
193 /* This is not compatible with y2038 */
194 date_and_time = packet;
195 dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time);
196}
197
198static void
199rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
200{
201 u32 packet;
202 int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
203 &packet, sizeof(packet));
204
205 if (ret)
206 return;
207
208 rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
209 -1, NULL, 0);
210}
211
212static void rpi_register_clk_driver(struct device *dev)
213{
214 struct device_node *firmware;
215
216 /*
217 * Earlier DTs don't have a node for the firmware clocks but
218 * rely on us creating a platform device by hand. If we do
219 * have a node for the firmware clocks, just bail out here.
220 */
221 firmware = of_get_compatible_child(dev->of_node,
222 "raspberrypi,firmware-clocks");
223 if (firmware) {
224 of_node_put(firmware);
225 return;
226 }
227
228 rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
229 -1, NULL, 0);
230}
231
232static int rpi_firmware_probe(struct platform_device *pdev)
233{
234 struct device *dev = &pdev->dev;
235 struct rpi_firmware *fw;
236
237 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
238 if (!fw)
239 return -ENOMEM;
240
241 fw->cl.dev = dev;
242 fw->cl.rx_callback = response_callback;
243 fw->cl.tx_block = true;
244
245 fw->chan = mbox_request_channel(&fw->cl, 0);
246 if (IS_ERR(fw->chan)) {
247 int ret = PTR_ERR(fw->chan);
248 if (ret != -EPROBE_DEFER)
249 dev_err(dev, "Failed to get mbox channel: %d\n", ret);
250 return ret;
251 }
252
253 init_completion(&fw->c);
254
255 platform_set_drvdata(pdev, fw);
256
257 rpi_firmware_print_firmware_revision(fw);
258 rpi_register_hwmon_driver(dev, fw);
259 rpi_register_clk_driver(dev);
260
261 return 0;
262}
263
264static void rpi_firmware_shutdown(struct platform_device *pdev)
265{
266 struct rpi_firmware *fw = platform_get_drvdata(pdev);
267
268 if (!fw)
269 return;
270
271 rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0);
272}
273
274static int rpi_firmware_remove(struct platform_device *pdev)
275{
276 struct rpi_firmware *fw = platform_get_drvdata(pdev);
277
278 platform_device_unregister(rpi_hwmon);
279 rpi_hwmon = NULL;
280 platform_device_unregister(rpi_clk);
281 rpi_clk = NULL;
282 mbox_free_channel(fw->chan);
283
284 return 0;
285}
286
287/**
288 * rpi_firmware_get - Get pointer to rpi_firmware structure.
289 * @firmware_node: Pointer to the firmware Device Tree node.
290 *
291 * Returns NULL is the firmware device is not ready.
292 */
293struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
294{
295 struct platform_device *pdev = of_find_device_by_node(firmware_node);
296
297 if (!pdev)
298 return NULL;
299
300 return platform_get_drvdata(pdev);
301}
302EXPORT_SYMBOL_GPL(rpi_firmware_get);
303
304/*
305 * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that
306 * implements xHCI. After a PCI reset, VL805's firmware may either be loaded
307 * directly from an EEPROM or, if not present, by the SoC's co-processor,
308 * VideoCore. RPi4's VideoCore OS contains both the non public firmware load
309 * logic and the VL805 firmware blob. This function triggers the aforementioned
310 * process.
311 */
312int rpi_firmware_init_vl805(struct pci_dev *pdev)
313{
314 struct device_node *fw_np;
315 struct rpi_firmware *fw;
316 u32 dev_addr, version;
317 int ret;
318
319 fw_np = of_find_compatible_node(NULL, NULL,
320 "raspberrypi,bcm2835-firmware");
321 if (!fw_np)
322 return 0;
323
324 fw = rpi_firmware_get(fw_np);
325 of_node_put(fw_np);
326 if (!fw)
327 return -ENODEV;
328
329 /*
330 * Make sure we don't trigger a firmware load unnecessarily.
331 *
332 * If something went wrong with PCI, this whole exercise would be
333 * futile as VideoCore expects from us a configured PCI bus. Just take
334 * the faulty version (likely ~0) and let xHCI's registration fail
335 * further down the line.
336 */
337 pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, &version);
338 if (version)
339 goto exit;
340
341 dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 |
342 PCI_FUNC(pdev->devfn) << 12;
343
344 ret = rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET,
345 &dev_addr, sizeof(dev_addr));
346 if (ret)
347 return ret;
348
349 /* Wait for vl805 to startup */
350 usleep_range(200, 1000);
351
352 pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET,
353 &version);
354exit:
355 pci_info(pdev, "VL805 firmware version %08x\n", version);
356
357 return 0;
358}
359EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805);
360
361static const struct of_device_id rpi_firmware_of_match[] = {
362 { .compatible = "raspberrypi,bcm2835-firmware", },
363 {},
364};
365MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
366
367static struct platform_driver rpi_firmware_driver = {
368 .driver = {
369 .name = "raspberrypi-firmware",
370 .of_match_table = rpi_firmware_of_match,
371 },
372 .probe = rpi_firmware_probe,
373 .shutdown = rpi_firmware_shutdown,
374 .remove = rpi_firmware_remove,
375};
376module_platform_driver(rpi_firmware_driver);
377
378MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
379MODULE_DESCRIPTION("Raspberry Pi firmware driver");
380MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Defines interfaces for interacting with the Raspberry Pi firmware's
4 * property channel.
5 *
6 * Copyright © 2015 Broadcom
7 */
8
9#include <linux/dma-mapping.h>
10#include <linux/kref.h>
11#include <linux/mailbox_client.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_platform.h>
15#include <linux/platform_device.h>
16#include <linux/slab.h>
17#include <soc/bcm2835/raspberrypi-firmware.h>
18
19#define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
20#define MBOX_CHAN(msg) ((msg) & 0xf)
21#define MBOX_DATA28(msg) ((msg) & ~0xf)
22#define MBOX_CHAN_PROPERTY 8
23
24static struct platform_device *rpi_hwmon;
25static struct platform_device *rpi_clk;
26
27struct rpi_firmware {
28 struct mbox_client cl;
29 struct mbox_chan *chan; /* The property channel. */
30 struct completion c;
31 u32 enabled;
32
33 struct kref consumers;
34};
35
36static DEFINE_MUTEX(transaction_lock);
37
38static void response_callback(struct mbox_client *cl, void *msg)
39{
40 struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
41 complete(&fw->c);
42}
43
44/*
45 * Sends a request to the firmware through the BCM2835 mailbox driver,
46 * and synchronously waits for the reply.
47 */
48static int
49rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
50{
51 u32 message = MBOX_MSG(chan, data);
52 int ret;
53
54 WARN_ON(data & 0xf);
55
56 mutex_lock(&transaction_lock);
57 reinit_completion(&fw->c);
58 ret = mbox_send_message(fw->chan, &message);
59 if (ret >= 0) {
60 if (wait_for_completion_timeout(&fw->c, HZ)) {
61 ret = 0;
62 } else {
63 ret = -ETIMEDOUT;
64 WARN_ONCE(1, "Firmware transaction timeout");
65 }
66 } else {
67 dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
68 }
69 mutex_unlock(&transaction_lock);
70
71 return ret;
72}
73
74/**
75 * rpi_firmware_property_list - Submit firmware property list
76 * @fw: Pointer to firmware structure from rpi_firmware_get().
77 * @data: Buffer holding tags.
78 * @tag_size: Size of tags buffer.
79 *
80 * Submits a set of concatenated tags to the VPU firmware through the
81 * mailbox property interface.
82 *
83 * The buffer header and the ending tag are added by this function and
84 * don't need to be supplied, just the actual tags for your operation.
85 * See struct rpi_firmware_property_tag_header for the per-tag
86 * structure.
87 */
88int rpi_firmware_property_list(struct rpi_firmware *fw,
89 void *data, size_t tag_size)
90{
91 size_t size = tag_size + 12;
92 u32 *buf;
93 dma_addr_t bus_addr;
94 int ret;
95
96 /* Packets are processed a dword at a time. */
97 if (size & 3)
98 return -EINVAL;
99
100 buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr,
101 GFP_ATOMIC);
102 if (!buf)
103 return -ENOMEM;
104
105 /* The firmware will error out without parsing in this case. */
106 WARN_ON(size >= 1024 * 1024);
107
108 buf[0] = size;
109 buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
110 memcpy(&buf[2], data, tag_size);
111 buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
112 wmb();
113
114 ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
115
116 rmb();
117 memcpy(data, &buf[2], tag_size);
118 if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
119 /*
120 * The tag name here might not be the one causing the
121 * error, if there were multiple tags in the request.
122 * But single-tag is the most common, so go with it.
123 */
124 dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
125 buf[2], buf[1]);
126 ret = -EINVAL;
127 }
128
129 dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr);
130
131 return ret;
132}
133EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
134
135/**
136 * rpi_firmware_property - Submit single firmware property
137 * @fw: Pointer to firmware structure from rpi_firmware_get().
138 * @tag: One of enum_mbox_property_tag.
139 * @tag_data: Tag data buffer.
140 * @buf_size: Buffer size.
141 *
142 * Submits a single tag to the VPU firmware through the mailbox
143 * property interface.
144 *
145 * This is a convenience wrapper around
146 * rpi_firmware_property_list() to avoid some of the
147 * boilerplate in property calls.
148 */
149int rpi_firmware_property(struct rpi_firmware *fw,
150 u32 tag, void *tag_data, size_t buf_size)
151{
152 struct rpi_firmware_property_tag_header *header;
153 int ret;
154
155 /* Some mailboxes can use over 1k bytes. Rather than checking
156 * size and using stack or kmalloc depending on requirements,
157 * just use kmalloc. Mailboxes don't get called enough to worry
158 * too much about the time taken in the allocation.
159 */
160 void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL);
161
162 if (!data)
163 return -ENOMEM;
164
165 header = data;
166 header->tag = tag;
167 header->buf_size = buf_size;
168 header->req_resp_size = 0;
169 memcpy(data + sizeof(*header), tag_data, buf_size);
170
171 ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header));
172
173 memcpy(tag_data, data + sizeof(*header), buf_size);
174
175 kfree(data);
176
177 return ret;
178}
179EXPORT_SYMBOL_GPL(rpi_firmware_property);
180
181static void
182rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
183{
184 time64_t date_and_time;
185 u32 packet;
186 int ret = rpi_firmware_property(fw,
187 RPI_FIRMWARE_GET_FIRMWARE_REVISION,
188 &packet, sizeof(packet));
189
190 if (ret)
191 return;
192
193 /* This is not compatible with y2038 */
194 date_and_time = packet;
195 dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time);
196}
197
198static void
199rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
200{
201 u32 packet;
202 int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
203 &packet, sizeof(packet));
204
205 if (ret)
206 return;
207
208 rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
209 -1, NULL, 0);
210}
211
212static void rpi_register_clk_driver(struct device *dev)
213{
214 struct device_node *firmware;
215
216 /*
217 * Earlier DTs don't have a node for the firmware clocks but
218 * rely on us creating a platform device by hand. If we do
219 * have a node for the firmware clocks, just bail out here.
220 */
221 firmware = of_get_compatible_child(dev->of_node,
222 "raspberrypi,firmware-clocks");
223 if (firmware) {
224 of_node_put(firmware);
225 return;
226 }
227
228 rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
229 -1, NULL, 0);
230}
231
232unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id)
233{
234 struct rpi_firmware_clk_rate_request msg =
235 RPI_FIRMWARE_CLK_RATE_REQUEST(id);
236 int ret;
237
238 ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
239 &msg, sizeof(msg));
240 if (ret)
241 /*
242 * If our firmware doesn't support that operation, or fails, we
243 * assume the maximum clock rate is absolute maximum we can
244 * store over our type.
245 */
246 return UINT_MAX;
247
248 return le32_to_cpu(msg.rate);
249}
250EXPORT_SYMBOL_GPL(rpi_firmware_clk_get_max_rate);
251
252static void rpi_firmware_delete(struct kref *kref)
253{
254 struct rpi_firmware *fw = container_of(kref, struct rpi_firmware,
255 consumers);
256
257 mbox_free_channel(fw->chan);
258 kfree(fw);
259}
260
261void rpi_firmware_put(struct rpi_firmware *fw)
262{
263 kref_put(&fw->consumers, rpi_firmware_delete);
264}
265EXPORT_SYMBOL_GPL(rpi_firmware_put);
266
267static void devm_rpi_firmware_put(void *data)
268{
269 struct rpi_firmware *fw = data;
270
271 rpi_firmware_put(fw);
272}
273
274static int rpi_firmware_probe(struct platform_device *pdev)
275{
276 struct device *dev = &pdev->dev;
277 struct rpi_firmware *fw;
278
279 /*
280 * Memory will be freed by rpi_firmware_delete() once all users have
281 * released their firmware handles. Don't use devm_kzalloc() here.
282 */
283 fw = kzalloc(sizeof(*fw), GFP_KERNEL);
284 if (!fw)
285 return -ENOMEM;
286
287 fw->cl.dev = dev;
288 fw->cl.rx_callback = response_callback;
289 fw->cl.tx_block = true;
290
291 fw->chan = mbox_request_channel(&fw->cl, 0);
292 if (IS_ERR(fw->chan)) {
293 int ret = PTR_ERR(fw->chan);
294 kfree(fw);
295 return dev_err_probe(dev, ret, "Failed to get mbox channel\n");
296 }
297
298 init_completion(&fw->c);
299 kref_init(&fw->consumers);
300
301 platform_set_drvdata(pdev, fw);
302
303 rpi_firmware_print_firmware_revision(fw);
304 rpi_register_hwmon_driver(dev, fw);
305 rpi_register_clk_driver(dev);
306
307 return 0;
308}
309
310static void rpi_firmware_shutdown(struct platform_device *pdev)
311{
312 struct rpi_firmware *fw = platform_get_drvdata(pdev);
313
314 if (!fw)
315 return;
316
317 rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0);
318}
319
320static void rpi_firmware_remove(struct platform_device *pdev)
321{
322 struct rpi_firmware *fw = platform_get_drvdata(pdev);
323
324 platform_device_unregister(rpi_hwmon);
325 rpi_hwmon = NULL;
326 platform_device_unregister(rpi_clk);
327 rpi_clk = NULL;
328
329 rpi_firmware_put(fw);
330}
331
332static const struct of_device_id rpi_firmware_of_match[] = {
333 { .compatible = "raspberrypi,bcm2835-firmware", },
334 {},
335};
336MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
337
338struct device_node *rpi_firmware_find_node(void)
339{
340 return of_find_matching_node(NULL, rpi_firmware_of_match);
341}
342EXPORT_SYMBOL_GPL(rpi_firmware_find_node);
343
344/**
345 * rpi_firmware_get - Get pointer to rpi_firmware structure.
346 * @firmware_node: Pointer to the firmware Device Tree node.
347 *
348 * The reference to rpi_firmware has to be released with rpi_firmware_put().
349 *
350 * Returns NULL is the firmware device is not ready.
351 */
352struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
353{
354 struct platform_device *pdev = of_find_device_by_node(firmware_node);
355 struct rpi_firmware *fw;
356
357 if (!pdev)
358 return NULL;
359
360 fw = platform_get_drvdata(pdev);
361 if (!fw)
362 goto err_put_device;
363
364 if (!kref_get_unless_zero(&fw->consumers))
365 goto err_put_device;
366
367 put_device(&pdev->dev);
368
369 return fw;
370
371err_put_device:
372 put_device(&pdev->dev);
373 return NULL;
374}
375EXPORT_SYMBOL_GPL(rpi_firmware_get);
376
377/**
378 * devm_rpi_firmware_get - Get pointer to rpi_firmware structure.
379 * @dev: The firmware device structure
380 * @firmware_node: Pointer to the firmware Device Tree node.
381 *
382 * Returns NULL is the firmware device is not ready.
383 */
384struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
385 struct device_node *firmware_node)
386{
387 struct rpi_firmware *fw;
388
389 fw = rpi_firmware_get(firmware_node);
390 if (!fw)
391 return NULL;
392
393 if (devm_add_action_or_reset(dev, devm_rpi_firmware_put, fw))
394 return NULL;
395
396 return fw;
397}
398EXPORT_SYMBOL_GPL(devm_rpi_firmware_get);
399
400static struct platform_driver rpi_firmware_driver = {
401 .driver = {
402 .name = "raspberrypi-firmware",
403 .of_match_table = rpi_firmware_of_match,
404 },
405 .probe = rpi_firmware_probe,
406 .shutdown = rpi_firmware_shutdown,
407 .remove_new = rpi_firmware_remove,
408};
409module_platform_driver(rpi_firmware_driver);
410
411MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
412MODULE_DESCRIPTION("Raspberry Pi firmware driver");
413MODULE_LICENSE("GPL v2");